According to a conventional write-once type recording medium such as a DVD-R, an entire recording area can be written only once physically. In other words, according to a write-once type recording medium, as shown in FIG. 4A, new data can be recorded only in a area starting from a NWA (Next Writable Address) 105 provided at a boundary between a recorded area 101 and an unrecorded area 104, and data recorded in the data-recorded area before the address of the NWA cannot be overwritten physically.
However, recently, a method capable of pseudo-overwriting of data in the recorded area of the write-once type recording medium has been developed. For example, a write-once type recording medium such as a BD-R (Blu-ray Disc Recordable Format) can be provided with a replacement management area while keeping the same characteristics as that of the conventional write-once type recording medium. In addition, a record/reproduction device (disk drive and the like) for a write-once type recording medium can perform a replacement process to such a write-once type recording medium. Thus, the replacement process enables recording (overwrite) of data to the recorded area, which is impossible for the conventional write-once type recording medium (refer to Non-Patent Document 1, for example). Such overwrite is referred to as the “pseudo overwrite” hereinafter.
With reference to FIG. 4B, the pseudo overwrite will be described. When data is overwritten in a partial area 102 of a recorded area 101, the data to be overwritten is recorded in an unrecorded area 103 starting from the NWA 105. Then, replacement information showing that the area 102 is replaced with the area 103 is recorded in a replacement management area in the recording medium. As a result of the replacement process replacing the area 102 with the area 103, a NWA 105b is newly set after the area 103. Note that management data is recorded in anywhere in the recording medium similar to user data.
This method allows pseudo overwrite of data to be achieved in the recorded area of the write-once type recording medium. However, since the pseudo overwrite is accompanied with the replacement process, the replacement information relating the areas to each other is generated. The replacement information is recorded in the write-once type recording medium, consuming the recording area. Thus the replacement process cannot be performed infinitely. That is, the number of times of the pseudo overwrite processes is limited in the write-once type recording medium. In addition, when the user data is overwritten in the above BD-R, it is necessary to record the user data in the area 103 in the unrecorded area 104 shown in FIG. 4B, and record the management data already recorded in the recorded area 101 and including an updated address of the user data recorded in the area 103 (refer to Patent Document 1, for example).    Patent Document 1: JP 09-259575 A    Non-Patent Document 1: Universal Disk Format Specification (Revision 2.60) 2005, chapter 152, 6.16.3